GU10 Birdies

[AndrewE]

Question for anyone who's used them: are the mains voltage birdies as good as the transformed MR-16 ones?

 

I'm looking to buy a few from Lighting Partners as they are reasonably priced and I hate faffing around with transformers.

 

Thanks,

 

Andrew

[peternewman]

I've got a few, and I certainly prefer the lamp socket over the rubbish bi-pin ones on the 12v ones we have, which always seem to fail, and the lamp itself pushes up inside the cone housing.

 

I think they're very similar in brightness, although I don't think I've ever managed to do a direct side to side comparison with the same beam angle in both types. Some people also claim they blow easily, however apart from one I knocked off a table when it was switched on, which did blow, I've not had any blow from knocks I don't think.

[paulears]

cpc ones are pretty cheap, bought a load in one of their offers a few weeks ago - can't find the link at the mo, will try later.

[Chris Beesley]

Hope the mods dont shoot me for this ... its in response to pauls post

 

The GU10 Birdies are in the brochure available below.

http://cpc.farnell.com/jsp/bespoke/bespoke...n_CC/sounds.jsp

[gunner]

I have 12 GU10 Birdies and have never had a problem with them. Like you I don't like having the transformers.

[Brian]

You can also get PAR20 and PAR30 which have mains ES lampholders.

[gareth]

The problem with GU10 birdies is that the selection of available lamps isn't nearly as wide as the range available in 12v GX5.3 lamps. We're currently faced with the prospect of having to remove a load of GU10 lampholders from a bunch of recessed light fittings (for the panto set) and replacing them with GX5.3 holders because the required beam angle isn't available in GU10.

[Ynot]

The problem with GU10 birdies is that the selection of available lamps isn't nearly as wide as the range available in 12v GX5.3 lamps.

The GU10's do seem to be quite a bit cheaper than the 12v jobbies, tho...

a GU10 is on Chris' flyer at £6.87 with a bubble at 80p.

The 12v Birdies are shown as £8.66 (black) plus £2.33 for a bubble, before you buy the transformer...

[gareth]

With all respect to Chris, that's why we don't buy our Birdies or MR16 lamps from CPC.

[Chris Beesley]

The MR16 birdies are manufactured in Italy by DTS - the GU10 birdies are a chinese product comissioned by HQ Power.

Thanks for your feedback guys... I will look into this one.

[Ekij]

I've heard (this is a second hand report, I've not enough experience to comment directly) that the filament in the 230V MR16 (GU10) is very fine and is very susceptible to vibration and knocks. Clearly in some applications this won't be an issue but if you are mounting somewhere were the can might get a knock or a bump or embedding in scenery that gets flown in and out this might be a consideration.

 

Certainly the transformers can be annoying as you need to mount them near to the CAN.

 

<dubious behaviour>

A nasty alternative is to wire a load in series with the 12V lamp and feed it 230V (such that only 12V is dropped across the 12V lamp). You will need to ensure that the connections and insulation are rated for 230V but provided that this is OK you can wire a 400W 230V lamp in series with a 12V 20W lamp to get 11.9V across the 12V lamp.

Similarly a 575W 230V lamp in series with a 12V 30W (11.4V)

and a 1000W 230V in series with a 50W (11.9V)

 

This behaviour is of course dubious for a variety of reasons and I expect to get flamed for menting as someone working on the 12V lamp might not be expecting it to have a 230V feed to it. If someone was to change the value of the lamps then it all goes wrong.

This is however not that dissimilar from a batton that has 10 * 12V lamps in series and fed from 230V

</dubious behaviour>

 

Edit: for some reason my "dubious behaviour" HTML markers got stripped!

[musht]

12V is more efficient than 23/40 V lamp, its also a much smaller filament in same size of reflector so beam can be controlled a lot more precisely.

 

Filament in 12V lamp is thick and pretty tough, GU10 whilst better than they were, are still a big run of thin filament in tight space, 12V lamps are definitely tougher.

 

Electronic transformers aren`t expensive just a bit of a pest to mount.

[Ekij]

12V is more efficient than 230/240 V lamp

How so?

I would have claimed the opposite as the 12V has the transformer losses that the 230V does not.

 

EDIT: Even ignoring the transformer, I fail to see how the lamp itself can be more efficient. The more curly the filament the more filament 'gets in the way' of other bits of the filament and blocks the light. A single straight strand is the most efficient filament (but is practically difficult to make).

[musht]

12V is more efficient than 230/240 V lamp

How so?

I would have claimed the opposite as the 12V has the transformer losses that the 230V does not.

 

EDIT: Even ignoring the transformer, I fail to see how the lamp itself can be more efficient. The more curly the filament the more filament 'gets in the way' of other bits of the filament and blocks the light. A single straight strand is the most efficient filament (but is practically difficult to make).

 

Transformer losses excluded ;-) modern switch mode should be 85%+ efficient though, same hocus pocus with LED and discharge lighting losing control gear losses out the headline numbers.

 

Cant lay my fingers on immediate reference but as far as remember 12V filament hits a sweet spot in the halogen cycle with the filament being short and thick and concentration of heat, will try and get a reference to it when get a sec.

[GridGirl]

I recently did a show where we had about 15 of the mains voltage birdies across the front of the stage; there was some pretty heavy dancing going on extremely near them, and several of them were booted more than once, but we didn't have any issues with large numbers of bubbles going. And they were much easier to cable up neatly without transformers to deal with!